首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8420篇
  免费   731篇
  国内免费   19篇
耳鼻咽喉   140篇
儿科学   232篇
妇产科学   145篇
基础医学   1250篇
口腔科学   369篇
临床医学   734篇
内科学   1729篇
皮肤病学   178篇
神经病学   760篇
特种医学   202篇
外国民族医学   1篇
外科学   1081篇
综合类   41篇
一般理论   1篇
预防医学   664篇
眼科学   155篇
药学   560篇
中国医学   44篇
肿瘤学   884篇
  2023年   39篇
  2022年   82篇
  2021年   219篇
  2020年   135篇
  2019年   261篇
  2018年   285篇
  2017年   192篇
  2016年   211篇
  2015年   253篇
  2014年   323篇
  2013年   389篇
  2012年   483篇
  2011年   566篇
  2010年   323篇
  2009年   274篇
  2008年   437篇
  2007年   480篇
  2006年   413篇
  2005年   400篇
  2004年   383篇
  2003年   361篇
  2002年   326篇
  2001年   202篇
  2000年   225篇
  1999年   182篇
  1998年   87篇
  1997年   78篇
  1996年   54篇
  1995年   58篇
  1994年   53篇
  1993年   54篇
  1992年   113篇
  1991年   135篇
  1990年   111篇
  1989年   125篇
  1988年   82篇
  1987年   84篇
  1986年   67篇
  1985年   58篇
  1984年   61篇
  1983年   33篇
  1982年   41篇
  1981年   38篇
  1980年   31篇
  1979年   49篇
  1977年   32篇
  1976年   33篇
  1974年   24篇
  1973年   26篇
  1971年   27篇
排序方式: 共有9170条查询结果,搜索用时 15 毫秒
1.
2.
Gangliocytic paragangliomas are rare tumors that almost exclusively occur within the second portion of the duodenum. Although these tumors generally have a benign clinical course, they have the potential to recur or metastasize to regional lymph nodes. The case report presented here describes a 57-year-old female patient with melena, progressive asthenia, anemia, and a mass in the second-third portion of the duodenum that was treated by local excision. The patient was diagnosed with a friable bleeding tumor. The histologic analysis showed that the tumor was a 4 cm gangliocytic paraganglioma without a malignant cell pattern. In the absence of local invasion or distant metastasis, endoscopic resection represents a feasible, curative therapy. Although endoscopic polypectomy is currently considered the treatment of choice, it is not recommended if the size of the tumor is > 3 cm and/or there is active or recent bleeding. Patients diagnosed with a gangliocytic paraganglioma should be closely followed-up for possible local recurrence.  相似文献   
3.
4.
5.
6.
7.
We report a case of localized bullous pemphigoid (BP) in a woman patient with primary lymphoedema tarda. There is only one previous case reported of localized pemphigoid in an area of lymphoedema, this being of the cicatricial variant. Slow circulation in the lymphatic vessels, increased capillary permeability with preferential localization of antibodies in the area, and potential cleavage of the epidermal junction due to increased hydrostatic pressure leading to autoimmunity, have all been advocated as possible pathogenic mechanisms. Nevertheless, we consider that the mechanism by which localized pemphigoid arises on lymphoedema remains elusive, based on a previous case of generalized BP sparing an area of postsurgical lymphoedema.  相似文献   
8.
We report the case of a patient infected with human immunodeficiency virus who presented with fever and a disseminated papulous eruption, diagnosed as cutaneous miliary tuberculosis. The diagnosis was made by histological examination of a skin biopsy, which showed numerous acid‐fast bacilli. A culture grown from a skin biopsy isolated a resistant Mycobacterium tuberculosis strain. The papules disappeared within a few days after starting treatment with pyrazinamide, isoniazid and moxifloxacin.  相似文献   
9.
In a study of 66 patients with systemic lupus erythematosus (SLE) and 80 controls it was found that the presence of two deficiency (null) alleles of C4 had a significant effect on mean C4 concentrations in serum. In six controls who each had two C4 null alleles the mean C4 concentration in serum was 56% lower than in 43 controls without C4 null alleles; the nadir of the C4 concentration in four patients with SLE with two null alleles was also lower by a mean of 55% than in 32 patients who did not have null alleles. Reduced production of C4 allotypes in subjects with two null alleles may be an important determinant of total C4 concentration in patients with SLE. For optimal interpretation of C4 concentrations in SLE, C4 allotyping appears to be indicated, particularly to identify patients who have two null alleles of C4.  相似文献   
10.
SETTING: Tuberculosis (TB) is frequent in human immunodeficiency virus (HIV) infected patients, but its treatment is hampered by adverse events and paradoxical reactions. OBJECTIVE: To examine the impact of HIV infection and other factors on the risk and spectrum of adverse events related to anti-tuberculosis treatment in a prospective cohort study conducted between January 2003 and August 2004. RESULTS: Of 105 patients treated for TB, 30 were HIV-infected. The overall incidence of adverse events was 122.5 +/- 18.5 per 100 patient-years (py) and the incidence of severe adverse events was 45.2 +/- 11.3/100 py. Age >50 years (OR 2.2, 95%CI 1.01-4.8, P = 0.046) and HIV infection (OR 3.9, 95%CI 2.1-7.5, P < 0.001) were independently associated with a higher risk of adverse events. Hepatitis (30.5/100 py) and neuropathy (28.6/100 py) were the most frequent adverse events. Hepatitis C virus infection was associated with hepatitis (OR 4.2, 95%CI 1.2-15.0, P = 0.028) and neuropathy with HIV infection (OR 3.8, 95%CI 1.1-13.7, P = 0.040). CONCLUSION: Adverse reactions to anti-tuberculosis drugs are frequent. HIV infection and age >50 years are factors associated with such reactions, while hepatitis C virus infection is a risk factor for hepatitis.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号